quote:

Originally posted by Beelzebubba:
My questions are:

- What rockwell hardness should the block be for .357 mag? I have access to some very modern maraging steels that are in the Rc 40 range in their normalized state. I also have access to 4130, but it moves when heat treated which might make the final fitting difficult. I'd prefer not to heat treat at all if its not necessary.

- I also intend to make a new firing pin that is 5/64" (.078") dia. How much protrusion should it have?

- Will leaving the firing pin assembly parallel to the flat on the bottom of the block work for centerfire?

- I'm currently trying to make the new block's profile identical to the old one, but should I expect to modify the "legs" on the rear of the block so it can open further for the .357 round?

I know these are some pretty specific questions, but I'm sure some of you can answer some of them. The good thing about making a whole new block is that I won't ruin the gun if I screw up and I can keep trying til I get it right. Thanks for your time - John

quote:

Originally posted by Beelzebubba:
Tentman, Sorry but its not possible or practical for me to make these for others. Thanks for the advice about the barrel shank, thats what I suspected and you saved me from having to find out the hard way.

Macifej, You're right, that's some tough material you're talking about. I wound up using some scrap 4340 Annealed from another part. It may be a little soft. I'll try to remember to test a piece tomorrow. If it is too soft, hopefully it won't move or shrink much when hardened. You seem to know a lot more than I do about metal, what can you tell me about it?

Thank you both for the replies - John

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333-OKH, I've never heard of the .22 Savage High Power, but I'll look into it.

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This old North American cartridge was designed by Charles Newton and commercialized by Savage in 1912. The .22 High-Power is based on the old .25-35 Winchester case necked down to accept .227-.228 inch bullets. Reloaders should note the odd bullet size; the .22 High-Power does not use standard .224" (5.56mm) diameter bullets. It is unusual in being a .22 that was designed as a combination varmint and deer cartridge.

The High-Power had a run of popularity in North America starting back before World War I, but the cartridge got a reputation as a wounder of deer. Eventually American shooters went back to larger caliber cartridges for deer hunting, and the .22 High-Power fell into disuse and eventual obsolescence.

The .22 High-Power retains a modest level of popularity in Europe where its rimmed case makes it adaptable to the break action combination guns and drillings beloved in the Old World. In Europe the High-Power is called the 5.6x52R because it uses a 5.6mm bullet in a rimmed case 52mm in length.

No factory loads have been offered by the Big Three North American ammo companies for the .22 Savage High-Power during my lifetime. The Lyman technicians chronographed some old Remington .22 Savage High-Power ammunition, and in the Lyman Reloading Handbook, 45th Edition they reported an instrumental velocity of 2624 fps 15 feet from the muzzle of a 20 inch barrel.

The High-Power is currently factory loaded in Europe as the 5.6x52R. Norma 5.6x52R factory loads are imported into the US. The Norma factory load uses a 71 grain soft point bullet at a muzzle velocity (MV) of 2789 fps with muzzle energy (ME) of 1227 ft. lbs. Norma trajectory figures show the following: +2.1" at 100 yards, 0 at 200 yards, and -9.9" at 300 yards.

The 5.6x52R can be reloaded, and the Hornady Handbook, Third Edition has data for reloaders. Data for European shooters is available in European reloading manuals. IMR 3031 is recommended as a good powder for the .22 High-Power. Hornady makes a 70 grain Spire-Point .227" bullet (BC .288, SD .194) specifically for the 5.6x52R, which they describe as a "varmint and small game round." Hornady's test rifle for developing the following loads was bolt action Mauser 66 and they advise that for old lever action rifles their maximum loads should be reduced by at least 10%.

Hornady data shows that their 70 grain Spire Point can be driven to a MV of 3100 fps with 28.3 grains of N203 powder, 27.4 grains of IMR 3031 powder, or 27.6 grains of N201 powder. The trajectory of that load looks like this: +1.6" at 100 yards, 0 at 200 yards, and -7.5" at 300 yards. These loads used RWS cases and Federal 210 primers.

quote:

Originally posted by Beelzebubba:
333-OKH, I've never heard of the .22 Savage High Power, but I'll look into it.

Macifej, You sound like a Vascomax salesman. There's no need to convince me, I've worked with it quite a bit. Its everything you say it is, but produces very long, sharp, stringy chips on a lathe unless you take cuts deep enough to require flood coolant and a very hefty machine. In fact, I cut my finger on some today.

Like I said above, this was a training project for me to work on during otherwise "down time," so I used what was readily available and cheap at the time. I tested the block today and it was only 7 on the Rockwell C scale. Not good enough. I've got my programs, but don't know when I would have the time to run them all over again. What's the best way to harden the 4340 annealed to a point that it can handle .22 Super Jet (read .223 Rem) pressures without warping or shrinking too much? If I do another breechblock some day, I'm considering 17-7 stainless, mainly because its cheaper, but also very good. Thanks - John